The present invention comprises a new and distinct cultivar of Hydrangea plant known by the varietal name ‘Stramadschi’. The new variety was discovered in 2003 in a planned breeding program in Salgen-Hausen, Germany. The purpose of the breeding program was to develop Hydrangeas with improved flower colors and black stems. The new variety is the result of a cross between seedling G6 (female parent, unpatented) and ‘Paris Rapa’ (male parent, U.S. Plant Pat. No. 10,906). The black stem color of ‘Stramadschi’ is similar to its female parent, but it differs from seedling G6 in flower color. The flowers of ‘Stramadschi’ are similar to ‘Paris Rapa’, but its leaf shape, black stem and red flower color are different from ‘Paris Rapa’. The new variety was first asexually reproduced in 2004 via propagation by cuttings in Salgen-Hausen, Germany. The new variety has been trial and field tested in Germany and has been found to retain its distinctive characteristics and remain true to type through successive propagations.
The following traits distinguish ‘Stramadschi’ as a new and distinct cultivar from other Hydrangea varieties known to the breeder:                1. Black stem color instead of green stem color;        2. Red flower color;        3. Frost resistance;        4. Stem strength; and        5. Mold resistance, such as botrytis.        
‘Stramadschi’ is similar to another Hydrangea variety, ‘Stramalyn’ (U.S. Plant patent application Ser. No. 12/384,252), because they both have black stems that are strong. However, ‘Stramadschi’ differs from ‘Stramalyn’ in flower color.